Vehicular upholstery polypropyleneterephthalate fiber fabric and method for producing of fabric

ABSTRACT

A vehicular upholstery fabric is made from a raw tricot fabric which is knitted by using a PPT-multifilament yarn whose single fiber fineness is about 0.5˜6.0 dtex and whose total fineness is about 30˜180 dtex for the ground yarn and the pile yarn. The raw tricot fabric has been transformed into a napped tricot pile fabric by raising the sinker loop of the pile yarn of the raw tricot fabric to form fluffs which are then sheared to form cut piles. A PPT-bulky multifilament yarn is used for the ground yarn. A PPT-non-bulky texturized multifilament yarn or a PPT-bulky texturized multifilament yarn is used for the pile yarn.

TECHNICAL FIELD

The present invention relates to a napped tricot pile fabric used for a vehicular upholstery which is knitted by applying a polypropylene-terephthalate fiber multifilament yarn to a ground yarn and a pile yarn and is finished by raising a sinker loop and by shearing napped fluffs to form cut pile.

BACKGROUND ART

In the napped tricot pile fabric used for the vehicular upholstery, a polyethleneterephth fiber multifilament yarn of which single fiber fineness is about 0.5˜6.0 dtex and total fineness is about 30˜180 dtex is applied generally to the ground yarn and the pile yarn.

The density of wale of cut pile is set up more than 30 W/25.4 mm.

The density of course of cut pile is set up more than 50 C/25.4 mm.

The density of knit loop, which is defined by the product of the density of wale of cut pile and the density of course of cut pile,is set up 1800˜2300 C×W/(25.4 mm)².

For preservation of the global environment, natual fibers such a cotton, linen, silk, wool, and a like are preferably used since these fibers do not depend on oil resources.

In this connection, a polypropyleneterephthalate fiber, hence called as “PPT-fiber”, and a polylacticacid fiber are is marked as thease synthetic fibers are productable of plant.

As disclosed in Japanese Patent Laid Open No. 2000-154457, Japanese Patent Laid Open No. 2002-004156,Japanese Patent Laid Open No. 2005-113279 and Japanese Patent Laid Open No. HEI-11-093050, the PPT-fiber and the polylacticacid fiber are tentatively used for a vehicular upholstery fabric.

Since the vehicular upholstery fabric is used under severe condition, a polyethleneterephth fiber, hence called as “PET-fiber”, is mainly used for the vehicular upholstery fabric.

Natual fibers and a rayon are lacking in durability.

So that, natual fibers and a rayon are not desirablly used for the vehicular upholstery fabric.

In this connection, PPT-fibers and polylacticacid fibers are expected as new meterials used for the vehicular upholstery fabric, since the chemical formula of polypropyleneterephthalate, hence called as “PPT”, and polylacticacid are similar to the chemical formulas of polypropyleneterephthalate, hence called as “PET”.

However, a polylacticacid fiber is lacking in corrosion resistance as it is one kind of biodegradability fibers.

And also, a polylacticacid fiber is lacking in dyeing property.

Therefore, in the case of application of the polylacticacid fiber for the vehicular upholstery fabric, it should be chemically reformed.

In this connection, in comparison with PET-fiber,young modulus of PPT-fiber is lower, late of an elastic recovery of PPT-fiber is higher, and PPT-fiber is rich in flexibility and stretching property.

So that, it is expected that the vehicular upholstery fabric having agreeable textile feeling will be obtained by using of PPT-fiber.

However, in the case of the napped tricot pile fabric which was knitted from PPT-multifilament yarn in place of PET-multifilament yarn, the cut-off-end-portion, where the fabric is cut off,easily curl.

Therefore, at the time of cutting and stacking up the napped tricot pile fabrics knitted from PPT-multifilament yarn, the curling of the cut-off-end-portion hinders to stack the cut tricot pile fabrics by arranging the cut-off-end-portions in order.

In addition, at the time of sewing the cut tricot pile fabrics, the cut-off-end-portion should be on the strain by pulling from one side to the other side to vanish the curling or should be pushed down to make the cut-off-end-portion plain.

So that, it takes a lot of time and labor to sew the cut tricot pile fabrics.

And, the curling of the cut-off-end-portion gives rise cutting miss and sewing miss.

Therefore, utility of the napped tricot pile fabric, which was knitted from PPT-multifilament yarn in place of PET-multifilament yarn, for the vehicular upholstery has been doubted.

Then, the cut-off-end-portion of the cut tricot pile fabric where PPT-fibers were used for the ground yarn(11) and the pile yarn(12) was minutely observed.

And, following matters were recognized.

(1) The curling does not arise at the cut-off-end-portion where the napped tricot pile fabric is cut along the knitting length direction(W).

(2) The curling arises at the cut-off-end-portion where the napped tricot pile fabric is cut along the knitting width direction(C) crossing the knitting length direction(W).

Simultaneously, in the case of PPT-multifilament yarn is used for the napped tricot pile fabric in place of PET-multifilament yarn, it seemed that following matters should be considered.

(1) The needle loop(14) and the sinker loop(13) are formed by swinging the ground yarn(11) and the pile yarn(12) in the knitting width direction(C).

(2) The ground yarn(11) and the pile yarn(12) in the napped tricot pile fabric are continuous in the knitting length direction(W).

(3) PPT-fiber is superior in stretching property(late of an elastic recovery) in comparison with PET-fiber which is comventionally used for the vehicular upholstery fabric.

(4) In comparison with PET-fiber, PPT-fiber shrinks easily by heating.

(5) The shrinking stress caused from and corresponding with the tension which acts to the raw tricot fabric made from PPT-fiber at the knitting process is larger than the shrinking stress caused from and corresponding with the tension which acts to the raw tricot fabric made from PET-fiber at the knitting process.

(6) The heat shrinking stress which occurs and acts to the raw tricot fabric made from PPT-fiber at the dyeing and finishing process is larger than the heat shrinking stress which occurs and acts to the raw tricot fabric made from PET-fiber at the dyeing and finishing process.

(7) The potential stress, which is stored in PPT-fiber at the knitting process and the dyeing and finishing process, manifests as the shrinking stress for giving rise the curling in the knitting length direction(W) where the ground yarn(11) and the pile yarn(12) are extending at the cutting and sewing process where the tensile stress(tension) does not act to the fabric.

On further investgation, in the case of PPT-multifilament yarn is used for the napped tricot pile fabric in place of PET-multifilament yarn, it seemed that following matters should be considered.

(1) In the case of the needle loop(14) does not form a lanky-shape configuration elongated in the knitting length direction(W) but forms a loop-like-shape configuration puffed in the knitting width direction(C), eventhough the ground yarn and the pile yarn shrink urged by the potential stress stored in those fibers, the needle loop(14) only turn into a loop-like-shape configuration from a lanky-shape configuration.

(2) Therefore, the course intervals(L), which is a size of needle loop in the knitting length direction, becoms hardly shortened.

(3) When the ground yarn(11) and the pile yarn(12) shrink, shrinkability of the napped tricot pile fabric in the knitting length direction(W) is relieved in accordance with the shrinking of the ground yarn(11) and the pile yarn(12).

(4) Consequently, the napped tricot pile fabric becomes hardly curl in the knitting length direction(W).

On furthermore investgation, in the case of PPT-multifilament yarn is used for the napped tricot pile fabric in place of PET-multifilament yarn, it seemed that following matters should be also considered.

(1) In the case of PPT-fiber used for the ground yarn(11) is a bulky-texturized fiber which is bent finely and tortuously and has crimps, eventhough the PPT-fiber shrinks urged by potential stress stored in it, only the crimps disappear and then PPT-fiber is brought into original non-bulky texturized situation.

(2) If the crimps only disappear at a time PPT-bulky texturized fiber shrinks, the course intervals(L) becoms hardly shortened.

(3) If the crimps only disappear at a time PPT-bulky texturized fiber shrinks, shrinkability of the napped tricot pile fabric in the knitting length direction(W) is relieved in accordance with the shrinking of the ground yarn(11) and the pile yarn(12).

(4) Consequently, the napped tricot pile fabric becomes hardly curl in the knitting length direction(W).

On furthermore investgation, in the case of PPT-multifilament yarn is used for the napped tricot pile fabric in place of PET-multifilament yarn, it seemed that following matters should be also considered.

(1) In the case of the PPT-fiber is not made of only PPT, that is, only polypropyleneterephthalate, but is made of PPT and PET, that is, polyethleneterephth of which young modulus is higher than the young modulus of PPT and of which late of elastic recovery,flexibility and stretching property are lower than late of elastic recovery, flexibility and stretching property of PPT, that is, in the case of the PPT-fiber is PPT-PET conjugate fiber made of PPT and PET,potential stress of PPT-PET conjugate fiber decreases in accordance with PET-component.

(2) Therefore,in the case of the PPT-PET conjugate fiber, eventhough the potential stress stored in it manifests, the shrinking stress caused from the potential stress decrease.

(3) Therefore, the napped tricot pile fabric becomes hardly curl in the knitting length direction(W) eventhough the potential stress stored in the PPT-PET conjugate fiber manifests.

On furthermore investgation,in the case of PPT-multifilament yarn is used for the napped tricot pile fabric in place of PET-multifilament yarn, it seemed that following matters should be also considered.

(1) In the case of the pile yarn is a twist yarn,strong raking stress is required at the raising process since the yarn is twistrd and it is hard to rake out the fibers of the pile yarn.

(2) And, at the process of that the strong raking stress(P) propagates from the sinker loop(13) to the needle loop(14), the strong raking stress (P) acts to the pile yarn as the tensile stress(Q).

(3) The tensile stress(Q) makes the needle loop(14) strained in the knitting length direction(W).

Then, the course intervals(L) becomes shortened.

(4) As a result, the substantial length of the portion of the ground yarn of the needle loop becomes relatively longer than the substantial length of the portion of the pile yarn of the needle loop(14).

(5) And, the ground yarn becomes loose in accordance with the parts of the ground yarn which are elongated.

(6) Therefore, when the potential stress manifests in the ground yarn, the loosened portion of the ground yarn only recovers its original form and its original length.

(7) That is, the course intervals(L) shortened by the tensile stress(Q) which acts to the pile yarn at raising is not shortened further by the potential stress which manifests in the ground yarn after raising.

(8) As a result, eventhough the potential stress stored in the ground yarn manifests as the shrinking stress, shrinking, which may be given rise by the shrinking stress in the knitting length direction(W) of the napped tricot pile fabric, is relieved.

Consequently, the napped tricot pile fabric becomes hardly curl in the knitting length direction(W).

DISCLOSURE OF INVENTION

The present invention was completed depending on above mentioned knowledge.

In accordance with the present invention, the vehicular upholstery PPT-fiber fabric is produced through follwing steps.

A raw tricot fabric is knitted by using PPT-multifilament yarn, of which single fiber fineness is 0.5˜6.0 dtex and total fineness is 30˜180 dtex, for the ground yarn(11) and the pile yarn(12).

The sinker loop(13) of pile yarn of the raw tricot fabric is napped to form fluffs.

The raw tricot fabric is transformed into a napped tricot pile fabric by shearing the napped fluffs to form cut piles.

The napped tricot pile fabric is spreaded neatly.

The spreaded napped tricot pile fabric is heated by straining in the knitting width direction(C) without straining in the knitting length direction(W).

Thereby relieves a potential stress of the needle loop(14) of the ground yarn(11) stored in at the knitting process.

At the same time, heat set the napped tricot pile fabric by the same heating so as the density of wale of cut pile is set up more than 30 W/25.4 mm, the density of course of cut pile is set up more than 50 C/25.4 mm, and the density of knit loop, which is defined by the product of the density of wale of cut pile and the density of course of cut pile, is set up 1800˜2300 C×W/(25.4 mm)².

The vehicular upholstery PPT-fiber fabric, in accordance with the present invention, has the first character comprised of following elements.

The raw tricot fabric is knitted by using PPT-multifilament yarn for the ground yarn(11) and the pile yarn(12).

The raw tricot fabric is transformed into a napped tricot pile fabric by napping the sinker loop(13) of pile yarn.

The napped fluffs of the sinker loop(13) form cut piles by shearing.

PPT-bulky multifilament yarn which may be called as “bulky texturized yarn” or simply called as “texturized yarn” is used for the ground yarn(11).

PPT-non-bulky texturized multifilament yarn, which may be called as “non-bulky texturized raw yarn” or simply called as “raw yarn”, or PPT-bulky texturiged multifilament yarn is used for the pile yarn(12).

The vehicular upholstery PPT-fiber fabric, in accordance with the present invention, has the second character comprised of following elements.

The raw tricot fabric is knitted by using PPT-multifilament yarn for the ground yarn(11) and the pile yarn(12).

The raw tricot fabric is transformed into a napped tricot pile fabric by napping the sinker loop(13) of pile yarn.

The napped fluffs of the sinker loop(13) form cut piles by shearing.

PPT-sheath core conjugate fiber multifilament yarn composed of core component-PET and sheath component-PPT of which amoumt in conjugate fiber is from 65 to 75 (weight percent) is used for at least the ground yarn(11) or the pile yarn(12).

The vehicular upholstery PPT-fiber fabric, in accordance with the present invention, has the third character comprised of following elements(a).

The raw tricot fabric is knitted by using PPT-multifilament yarn for the ground yarn(11) and the pile yarn(12).

The raw tricot fabric is transformed into a napped tricot pile fabric by napping the sinker loop(13) of pile yarn.

The napped fluffs of the sinker loop(13) form cut piles by shearing.

PPT-non-bulky texturized multifilament yarn is used for the ground yarn(11).

PPT-bulky texturized multifilament twist yarn is used for the pile yarn(12).

The vehicular upholstery PPT-fiber fabric, in accordance with the present invention, has the forth character comprised of following elements(a).

The single fiber fineness of PPT-multifilament yarn is 0.5˜6.0 dtex.

The total fineness of PPT-multifilament yarn is 30˜180 dtex.

The density of wale of the vehicular upholstery PPT-fiber fabric is more than 30 W/25.4 mm.

The density of course of the vehicular upholstery PPT-fiber fabric is more than 50 C/25.4 mm.

The density of knit loop of the vehicular upholstery PPT-fiber fabric, where the density of knit loop is defined by the product of the density of wale and the density of course, is 1800˜2300 C×W/(25.4 mm)².

The basis weight of the vehicular upholstery PPT-fiber fabric, where the basis weight is just about the weight of raw fabric, is more than 450 g/m².

The degree of curling in the knitting width direction and in the knitting length direction is respectively less than 20.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a plain view of the raw tricot fabric.

BEST MODE FOR CARRYING OUT THE INVENTION

In accordance with the present invention, PPT-bulky texturiged multi-filament yarn is used for the ground yarn(11).

So that, at a time PPT-fiber of the ground yarn(11) shrinks urged by potential stress stored in it, only the crimps disappear and PPT-fiber is brought into original non-bulky texturized situation.

That is, the potential stress which manifests in PPT-fiber is absorbed into the distortion which is given rise in accordance with the modification from bulky texturized situation to non-bulky texturized situation of PPT-fiber of the ground yarn(11).

On the other hand,most of PPT-fiber of the pile yarn pile yarn(12) has beem cut,shortened and transformed to fluffs of cut pile.

So that, eventhough potential stress has beem stored in and manifests in PPT-fiber of the pile yarn pile yarn(12), the potential stress does not manifest so strong that the course intervals(L) becomes shortened.

So that, eventhough potential stresses have beem stored in the ground yarn(11) and pile yarn pile yarn(12) manifest, the curling hardly appears at the cut-off-end-portion.

In the present invention,it need not always to form the ground yarn(11) and pile yarn pile yarn(12) by using only PPT-fiber.

That is, PPT-PET conjugate fiber composed of PPT-component and PET-component, which is higher in young modulus and lower in late of elastic recovery, flexibility and stretching property in comparison with PPT, is preferably used not only for the ground yarn(11) but also for the pile yarn pile yarn(12).

The application of PET-component make the potential stress decreased.

So that, due to the effect of PET-component, evenif potential stresses have beem stored in the ground yarn(11) or the pile yarn pile yarn(12) manifest, the curling becomes hardly appear at the cut-off-end-portion.

Further, in comparison with the pile yarn only composed of PPT-fiber, stretching property of the pile yarn composed of PPT-PET conjugate fiber is inferior.

So that, in the case of the application of PPT-PET conjugate fiber to the pile yarn, the raking stress(P) which acts to the sinker loop of the pile yarn easily propagates to the needle loop at raising.

And, the needle loop(14) of the pile yarn is easily pulled out by the raking stress(P).

And, the course intervals(L) becomes shortened according to the amount of the parts of the needle loop(14) which are pulled out.

At the time, since the ground yarn is not pulled out by the raking stress(P), the looseness occurs in the ground yarn in accordance with the amount of the parts of the needle loop(14) pulled out by the raking stress(P).

Therefore, when the potential stress manifests in the ground yarn, the loosened portion of the ground yarn only recovers its original form and its original length.

As mentioned above, the curling at the cut-off-end-portion is not effected in the knitting length direction(W) by the raking stress(P) which causes from the potential stress and manifests in the ground yarn, since the raking stress(P) is absorbed into the looseness of the ground yarn.

In the present invention, PPT-bulky texturized multifilament twist yarn is used for the pile yarn(12).

Then, it needs powerful raking stress(P) to raise the twist yarn.

So that, at the raising process, the raking stress(P) acts violently to the pile yarn as it is a twist yarn.

The raking stress(P) is propagated to the needle loop of the pile yarn through the sinker loop(13) at raising.

And then, the raking stress(P) acts as the tensile stress(Q) to pull out the needle loop(14) of the pile yarn.

As a result, the course intervals(L) becomes shortened according to the amount of the parts of the needle loop(14) which are pulled out.

And, the substantial length of the portion of the ground yarn of the needle loop becomes relatively longer than the substantial length of the portion of the pile yarn of the needle loop(14).

And, the ground yarn becomes loose in accordance with the parts of the ground yarn which are relatively elongated.

Therefore, when the potential stress manifests in the ground yarn, the loosened portion of the ground yarn only recovers its original form and its original length.

So that, the course intervals(L) shortened by the tensile stress(Q) which acts to the pile yarn at raising is not shortened further by the potential stress which manifests in the ground yarn after raising.

And, shrinking in the knitting length direction(W) of the napped tricot pile fabric is relieved.

Therefore, the curling in the knitting length direction(W) hardly appears at the cut-off-end-portion of the vehicular upholstery PPT-fiber fabric, even the PPT-non-bulky texturized multifilament yarn has been used for the ground yarn(11).

The number of twist of the pile yarn may be less than 120 (times/m).

In the case of the pile yarn(12) is twisted, the carding needle of the raising-roll does not separately scratch each fiber of the pile yarn(12) but scratchs all fibers as one lot.

However, it is rather difficult to scratchs all fibers as one lot in comparison with the case of scratching each fiber separately.

That is, in the case of the pile yarn(12) is twisted, it is difficult to raise the pile yarn(12).

So that, in the case of raising of twisted pile yarn(12), it needs to raise the pile yarn(12) with powerful raking stress(P).

In such a case, the needle loop(14) of pile yarn can be pulled violently.

So that, in the case of the number of twist is too much, it becomes difficult to raise the pile yarn(12).

Then, the number of twist of pile yarn set up less than 120 (times/m).

Conventional napped tricot pile fabric used for a vehicular upholstery fabric is knitted by using PET-multifilament yarn,of which single fiber fineness is 0.5˜6.0 dtex and total fineness is 30˜180 dtex, for the ground yarn(11) and the pile yarn(12).

The sinker loop(13) of pile yarn of the raw tricot fabric is napped to form fluffs.

The raw tricot fabric is transformed into a napped tricot pile fabric by shearing the napped fluffs to form cut piles.

Density of wale of the conventional napped tricot pile fabric is set up as well as that of the present invention more than 30 W/25.4 mm.

Density of course of the conventional napped tricot pile fabric is set up as well as that of the present invention more than 50 C/25.4 mm.

The density of knit loop defined by the product of the density of wale of cut pile and the density of course of cut pile of the conventional napped tricot pile fabric is set up as well as that of the present invention 1800˜2300 C×W/(25.4 mm)².

Therefore, in accordance with the present invention, the vehicular upholstery PPT-fiber fabric, which can be used as a replacement of conventional vehicular upholstery fabric and does not curl at the cut-off-end-portion, can be obtained.

On the process of the configuration of the needle loop(14) transforms into puffed-loop shape strained in the knitting width direction(C), the napped tricot pile fabric is under non-strain situation in the knitting length direction(W).

On such process, the load to prevent the transforming in the knitting width direction(C) does not act in the knitting length direction(W).

Therefore, the needle loop(14) hardly transforms into lanky shape which is lanky in the knitting length direction(W).

That is, the needle loop(14) hardly transforms into puffed-loop shape which is puffed in the knitting width direction(C).

And, eventhough the potential stress, which has beem stored in PPT-fiber of the puffed-loop shape needle loop(14) puffed in the knitting width direction(C), manifests, the puffed-loop shape of the needle loop(14) only transforms into lanky shape.

That is, eventhough the puffed-loop shape of the needle loop(14) transforms into lanky shape, the course intervals(L) does not shorten.

Therefore, in accordance with the present invention, the vehicular upholstery PPT-fiber fabric which hardly curl in the knitting length direction(W) can be obtained.

As mentioned adove,in accordance with the present invention, the vehicular upholstery PPT-fiber fabric which does not curl at the cut-off-end-portion at cutting and sewing process and can be made up efficiently into the vehicular upholstery material is obtained.

In the present invention, “basis weight of the vehicular upholstery PPT-fiber fabric” means that the density of wale of the vehicular upholstery PPT-fiber fabric is equal to the density of wale of the raw tricot fabric.

And, “basis weight of the vehicular upholstery PPT-fiber fabric” also means that the density of course of the vehicular upholstery PPT-fiber fabric is equal to the density of course of the raw tricot fabric.

That is, in the present invention, “basis weight” means the weight of imaginary raw knitted fabric of which density of wale and density of course are imagined respectively equal to density of wale and density of course of the vehicular upholstery PPT-fiber fabric which is finished up as goods through raising treatment, swelling treatment, dyeing treatment, and the like.

That is, in the present invention,signification of “basis weight” is that the “basis weight” can be used as the means to know the weight of base knitted fabric which is imagined that it may be remained when the pile remove away from the vehicular upholstery PPT-fiber fabric.

The reason to use the “basis weight” as the means to know the weight of base knitted fabric is as follows.

-   (1) Degree of curling of the vehicular upholstery PPT-fiber fabric     is variable in accordance with the density of the bulk of fabric. -   (2) The degree of curling can not be presumed by the fabric which is     remained when the pile cut away from the vehicular upholstery     PPT-fiber fabric. -   (3) Because, the pile is one portion of the pile yarn napped and     projected from the base knitted fabric, and eventhough the pile is     cut away,one part of the pile is remained among the base knitted     fabric. -   (4) Therefore,it is difficult to know the juncture between the base     knitted fabric and the remained part of the pile. -   (5) And, the degree of curling can not be compared with the density     of the bulk of the base knitted fabric. -   (6) And, the weight of the vehicular upholstery PPT-fiber fabric is     variable in accordance with the amount of pile fibers removed away     at raising and the height of pile. -   (7) Therefore, the degree of curling can not be compared with the     weight of the vehicular upholstery PPT-fiber fabric. -   (8) However, the weight of the base knitted fabric of the vehicular     upholstery PPT-fiber fabric is in proportion to the weight of the     raw tricot fabric. -   (9) So that,in the present invention, the “basis weight” is used as     the means to know the weight of base knitted fabric.

In the present invention, the degree of curling is measured by follwing steps.

-   (1) Test piece,of which size is “20 cm in the knitting length     direction×20 cm in the knitting width direction”, is picked out from     the vehicular upholstery PPT-fiber fabric. -   (2) The test piece is left in free for 24 hours. -   (3) The test piece is spreaded neatly over the metallic plate which     is mounted on the surface of the horizontal table, of which weight     is 180 g, and of which size is “22.5 cm in lengthwise×30 cm in     crosswise×1.0 mm in thickness”. -   (4) A metallic plate of which weight is 180 g and of which size is     “22.5 cm in lengthwise×30 cm in crosswise×1.0 mm in thickness” is     mounted on the test piece. -   (5) A plummet of which weight is 500 g is mounted on the center of     the metallic plate and is left for 10 minutes. -   (6) The plummet and the metallic plate are removed and the test     piece is left in free for 10 minutes. -   (7) Height from the surface of the metallic plate to the     end(edge)portion of the test piece which is bent up from the surface     of the metallic plate is measured.

The measuring is carried out total 2 times by directing the pile surface of test piece downward 1 time and by directing the pile surface of test piece upward 1 time.

The degree of curling is detamined by muximum measured value.

The degree of curling is indicated by the unit of “mm”.

The measuring is carried out under atmosphere of 20° C.×humidity 60%.

PPT-fiber is produced by polyconensation of terephthalic acid and such diol as 1-3-propandiol, 1-2-propandiol, 1-1-propandiol,2-2-propandiol,and the like.

PPT-fiber may be called as polytrimethyleneterephthalate fiber so called “PTT-fiber”.

One kind of PPT-fiber is made of petroleum.

However,in connection with preservation of the global environment, it is desirable to use the PPT-fiber which is made of plant.

Especially,it is further encouraged to use the PPT-fiber which is made by polyconensation of 1-3-propandiol and terephthalic acid.

Embodiment

7 kinds of PPT-fiber raw tricot fabrics and 1 kind of PET-fiber raw tricot fabric were respectively dyed and dried by heating.

Subsequently, the sinker loop of pile yarn of these fabric were raised through the raising apparatus.

Subsequently, the raised fluffs of these fabric were trasformed into cut piles through the shearing apparatus.

Finished thickness(total thickness) of these napped tricot pile fabric were respectively about 1.8 mm.

Subsequently, these napped tricot pile fabric were strained in the knitting width direction(C) without straining in the knitting length direction(W) and simultaneously heated at 150° C. through heat setting apparatus.

5 kinds of 8 kinds of PPT-fiber napped tricot pile fabric are Embodiments of the present invention.

2 kinds of 8 kinds of PPT-fiber napped tricot pile fabric are Comparisons.

Another 1 kind of 8 kinds of PPT-fiber napped tricot pile fabric indicates Conventional art.

Degree of curling, Breaking strength, Degree of softness and hardness, Elastic recovery property of pile, Knitting textile design, Standard of finished fabric, Standard of ground yarn, Standard of pile yarn and Measured value of physical property of these napped tricot pile fabric are shown in the tabul 1 .

In the present invention, the degree of softness and hardness is measured by follwing steps according with JIS-L-1018(Japanese Industrial Standard L-1018).

-   (1) Test pieces,one of which is lanky in the knitting length     direction and another of which is lanky in the knitting width     direction,are picked out from the napped tricot pile fabric. -   (2) The test piece is mount on the flat and horizontal surface of     table of which one end side portion is sloping surface inclined with     an inclination of 45 degrees. -   (3) At the time,one edge portion in the longitudinal direction of     the test piece is set at the ridgeline between the sloping surface     and the flat and horizontal surface of table. -   (4) Distance from the another edge portion of the test piece to the     ridgeline of the table is measured. -   (5) Subsequently, the test piece is pushed out towar the sloping     surface side to project the another edge portion of the test piece     over the sloping surface. -   (6) Pushing is stopped when the projected another edge portion of     the test piece hangs down and touchs on the sloping surface. -   (7) Moved distance of the test piece is measured. -   (8) The degree of softness and hardness of the napped tricot pile     fabric is detamined by the moved distance of the test piece. -   (9) The degree of softness and hardness is indicated by the unit of     “mm”.

In the present invention, the elastic recovery property of pile is measured by follwing steps.

-   (1) Test piece is picked out from the napped tricot pile fabric by     cutting in voluntary size.

The test piece is left under loading of 0.5N/cm²(50 gf/cm²) for 2 hours in the thermostat tank of 80° C.

-   (2) After loading, the test piece is take out from the thermostat     tank and is set under observation. -   (3) Elastic recovery property of pile of the test piece over which     collapsed piles or inclined piles are not observed at all is     estimated “5-class”. -   (4) Elastic recovery property of pile of the test piece over which     inclined piles are slightly observed but are not scarcely noticed is     estimated “4-class”. -   (5) Elastic recovery property of pile of the test piece over which     inclined piles are observed but are not noticed is estimated     “3-class”. -   (6) Elastic recovery property of pile of the test piece over which     collapsed piles or inclined piles are clearly observed is estimated     “2-class”. -   (7) Elastic recovery property of pile of the test piece over which     markedly inclined piles are observed is estimated “1-class”.

As obvious in comparison to Comparisons 1 and 2, in the case of the napped tricot pile fabric in accordance with Embodiments 1, 2, 3 and 4 wherein the non-bulky-texturized multifilament yarn is not used for the ground yarn, potential stress stored in the ground yarn has turned into shrinking stress and has manifested.

In the case of Embodiments 1 and 2, shrinking stress turned from the potential stress has absorbed into the transformed distortion of ground yarn which gives rise in accordance with the modification from bulky texturized situation to non-bulky texturized situation.

And, in the case of Embodiments 3 and 4 where PPT-sheath core conjugate fiber multifilament yarn composed of core component-PET and sheath component-PPT of which amoumt in conjugate fiber is 70 (weight percent) is used for the ground yarn(11) and the pile yarn(12), shrinking stress caused from sheath component-PPT is offset by core component-PET and does not act to make the course intervals(L) shortened.

So that, the degree of curling of the napped tricot pile fabrics in accordance with Embodiments 1, 2, 3 and 4 is low.

The density of knit loop of the Comparisons 1 and 2 where the non-bulky-texturized multifilament yarn is used for the ground yarn denser than the density of knit loop of the Embodiments 1, 2, 3 and 4.

Therefore, in the case of the Comparisons 1 and 2, potential stress stored in the ground yarn easily turn into shrinking stress and manifests.

And, the shrinking stress acts to make the course intervals(L) shortened in the knitting length direction.

So that, the napped tricot pile fabric,in accordance with Comparisons 1 and 2, tends to curl in the knitting length direction.

In the case of the Embodiment 5, as well as Comparisons 1 and 2, the non-bulky-texturized multifilament yarn is used for the ground yarn.

However, the degree of curling in the case of Embodiment 5 is lower than the degree of curling in the case of Comparisons 1 and 2.

The reason for it is seemed that the pile yarn used in Embodiment 5 is twisted.

That is,it is difficult to raise the twisted pile yarn.

So that,in the case of raising of twisted pile yarn(12), it needs to raise the pile yarn(12) with powerful raking stress(P) as shown in FIG. 1.

The strong raking stress(P) propagates from the sinker loop(13) to the needle loop(14).

And, the strong raking stress(P) is transformed into the tensile stress(Q) to act to the needle loop(14) of twisted pile yarn.

Then, the twisted pile yarn of the needle loop(14) is pulled out.

And then, the course intervals(L) becomes shortened.

As a result, the substantial length of the portion of the ground yarn of the needle loop becomes relatively longer than the substantial length of the portion of the twisted pile yarn of the needle loop(14).

Consequently, the ground yarn(11) becomes loose and the looseness appears on the ground yarn(11) in accordance with the parts of the ground yarn which are elongated.

Therefore, when the potential stress manifests in the fiber of ground yarn(11), the looseness is only removed from the fiber.

So that, eventhough the fiber shrinks, the shrinking of the fiber of ground yarn(11) hardly make the course intervals(L) shortened.

On the other hand,if the ground yarn(11) of the needle loop(14) is brought into a loosed situation, the napped tricot pile fabric becomes non-shrinkable in the knitting length direction(W).

Therefore, the curling hardly appears at the cut-off-end-portion of the napped tricot pile fabric of which the pile yarn has been twisted.

FIG. 1 shows the raw tricot fabric which is indicated in [Table 1].

The first reed(L₁) for ground yarn or the second reed(L₂) for ground yarn is knitting with a movement of . . . . . . . . . /1-2/1-0/1-2/1-0/1-2/1-0/ . . . . . . . . . for formation of knitting textile design.

The first reed(L₃) for pile yarn or the second reed(L₄) for pile yarn is knitting with a movement of . . . . . . . . . /1-0/4-5/1-0/4-5/1-0/4-5/ . . . . . . . . . for formation of knitting textile design.

Marks W₁, W₂, W₃, W₄ and W₅ indicate five wales where the sinker loop(13) is continuous.

In accordance with Embodiments 1, 2, 3, 4 and 5, it is encouraged for prevention of curling to set up the specifications of the vehicular upholstery PPT-fiber fabric as follows.

-   (1) PPT-bulky texturiged multifilament yarn should be used for the     ground yarn (Embodiments 1 and 2). -   (2) PPT-non-bulky texturized multifilament yarn or PPT-bulky     texturiged multifilament yarn should be used for the pile yarn     (Embodiments 1 and 2). -   (3) Preferably, PPT-non-bulky texturized multifilament yarn should     be used for the pile yarn (Embodiment 1). -   (4) Further preferably, PPT-sheath core conjugate fiber     multifilament yarn composed of core component-PET and sheath     component-PPT of which amoumt in conjugate fiber is from 65 to 75     (weight percent) should be used for both ground yarn and pile yarn     (Embodiments 3 and 4). -   (5) Especially,so as to keep the balance between the breaking     strengths in the knitting length direction and the knitting width     direction, the PPT-sheath core conjugate fiber multifilament yarn     should be used for both ground yarn and pile yarn (Embodiments 3 and     4). -   (6) In the case of that PPT-non-bulky texturized multifilament yarn     is oblige to use for the ground yarn, PPT-multifilament twist yarn     should be used for the pile yarn (Embodiment 5).

TABLE 1 Embodi- Embodi- Embodi- Embodi- Embodi- Compari- Compari- ment ment ment ment ment son son Conven- 1 2 3 4 5 1 2 tional knitting the first Leed(L₁) for ground yarn 1-2/1-0 1-2/1-0 1-2/1-0 1-2/1-0 1-2/1-0 1-2/1-0 1-2/1-0 1-2/1-0 textile the second Leed(L₂) for ground yarn 1-0/1-2 1-0/1-2 1-0/1-2 1-0/1-2 1-0/1-2 1-0/1-2 1-0/1-2 1-0/1-2 design the first Leed(L₃) for pile yarn 1-0/4-5 1-0/4-5 1-0/4-5 1-0/4-5 1-0/5-6 1-0/4-5 1-0/4-5 1-0/5-8 the second Leed(L₄) for pile yarn 1-0/4-5 1-0/4-5 1-0/4-5 1-0/4-5 . . . 1-0/4-5 1-0/4-5 1-0/5-6 Standard raw fabric density of wale(W/25.4 mm) 28 28 28 28 28 28 28 28 of density of course(C/25.4 mm) 70 68 56 56 50 61 61 61 manu- basis weight (g/m²) 520 544 377 386 384 404 395 388 factures knitting width (cm) 203 203 203 203 203 203 206 195 finished density of wale (W/25.4 mm) 36 35 34 34 35 37 37 35 fabric density of course (C/25.4 mm) 60 63 63 62 58 71 68 58 density knit-loop(C × W) 2160 2205 2142 2108 2030 2627 2516 2030 finished weight (g/m²) 383 412 466 482 519 599 509 405 finished width (cm) 156 163 167 167 154 150 156 156 thickness (mm) 2.10 1.80 1.65 1.80 1.80 1.80 2.00 2.00 basis weight (g/m²) 573 630 515 519 556 621 582 462 Standard PET-bulky single fiber fineness(dtex) . . . . . . . . . . . . . . . . . . . . . 2.3 of texturiged total fineness (dtex) . . . . . . . . . . . . . . . . . . . . . 84 ground multi f.y. yarn PPT single fiber fineness(dtex) . . . . . . 2.3 1.75 2.3 2.3 3.5 . . . non-bulky total fineness (dtex) . . . . . . 84 84 84 84 84 . . . texturiged rate of core component(%) . . . . . . PET 30% PET 30% . . . . . . . . . . . . multi f.y. PPT-bulky single fiber fineness(dtex) 2.3 2.3 . . . . . . . . . . . . . . . . . . texturiged total fineness (dtex) 84 84 . . . . . . . . . . . . . . . . . . multi f.y. Standard PET-bulky single fiber fineness(dtex) . . . . . . . . . . . . . . . . . . . . . 2.3 of texturiged total fineness (dtex) . . . . . . . . . . . . . . . . . . . . . 84 pileyarn multi f.y. PPT single fiber fineness(dtex) 1.75 . . . 2.3 1.75 . . . 1.75 3.5 . . . non-bulky total fineness (dtex) 84 . . . 84 84 . . . 84 84 . . . texturiged rate of core component(%) . . . . . . PET 30% PET 30% . . . . . . . . . . . . multi f.y. PPT-bulky single fiber fineness(dtex) . . . 2.3 . . . 1.75 2.3 1.75 . . . . . . texturiged total fineness (dtex) . . . 84 . . . 84 84 84 . . . . . . multi- number of the twist (T/m) . . . . . . . . . . . . 90 . . . . . . . . . filament rate of core component(%) . . . . . . . . . PET 30% . . . . . . . . . . . . yarn Physical dgree of in knitting length direction 4 15 2 3 11 34 31 1 property curling in knitting width direction 0 0 0 0 0 0 0 0 (mm) breaking in knitting length direction 128 119 90 98 119 124 128 182 strength in knitting width direction 70 78 82 82 78 88 82 113 (N/5 cm) degree of in knitting length direction 36 48 40 42 33 80 38 36 softness in knitting width direction 33 37 35 35 26 56 31 30 (mm) elastic recovery property of pile(Class) 2 3 2.5 3 3 2.5 2.5 3.5

INDUSTRIAL APPLICABILITY

In accordance with the present invention, the vehicular upholstery PPT-fiber napped tricot pile fabric, which does not curl at the cut-off-end-portion, and which is preferable for preservation of the global environment, is obtained. 

1. A vehicular upholstery polypropyleneterephthalate fiber fabric, comprising: a raw tricot fabric which is knitted—by using polypropyleneterephthalate-multifilament yarn, for the ground yarn and the pile yarn; wherein the raw tricot fabric is transformed—into a napped tricot pile fabric by raising—the sinker loop of the pile yarn—of the raw tricot fabric to form fluffs, which are then sheared to form cut piles; a polypropyleneterephthalate-textured multifilament yarn is used for the ground yarn; and a polypropyleneterephthalate-non-textured multifilament yarn—or a polypropyleneterephthalate-bulky textured multifilament yarn is used for the pile.
 2. A vehicular upholstery polypropyleneterephthalate fiber fabric, comprising: a vehicular upholstery fabric is made from a raw tricot fabric which is knitted by using polypropyleneterephthalate-multifilament yarn for the ground yarn and the pile yarn; wherein the raw tricot fabric is transformed—into a napped tricot pile fabric by raising—the sinker loop of the pile yarn—of the raw tricot fabric to form fluffs which are then sheared to form cut piles; and a polypropyleneterephthalate core-in-sheath core conjugate fiber multifilament yarn composed of a core component-polyethyhleneterephthalate and—a sheath component-polypropyleneterephthalate whose conjugate fiber is from 65 to 75 (weight percent)—is used for at least the ground yarn or the pile yarn.
 3. A vehicular upholstery—polypropyleneterephthalate fiber fabric, ‘comprising: a raw tricot fabric which is knitted by using polypropyleneterephthalate-multifilament yarn, for the ground yarn and the pile yarn; wherein the raw tricot fabric is transformed—into a napped tricot pile fabric by raising—the sinker loop of the pile yarn—of the raw tricot fabric to form fluffs which are then sheared to form cut piles; a polypropyleneterephthalate-non-textured multifilament yarn—is used for the ground yarn; and a polypropyleneterephthalate-textured multifilament twist yarn—is used for the pile yarn.
 4. A vehicular upholstery—polypropyleneterephthalate fiber fabric according to claims 1, wherein: the single fiber fineness of the polypropylenetherephthalate-multifilament yarn is 0.5˜6.0 dtex; the total finess of polypropyleneterephthalate-multifilament yarn is 30˜180 dtex; the density of the wale of the vehicular upholstery polypropyleneterephthalate-fiber fabric is more than 30 W/25.4 mm; the density of the course of the vehicular upholstery polypropyleneterephthalate-fiber fabric is more than 50 C/25.4 mm; the density of the knit looop, which is defined by the product of the density of the wale and the density of the course, is 1800 to 2300 C×W/(25.4 mm)²; the basis weight of the vehicular upholstery polypropyleneterephthalate-fiber fabric has been set at more than 450 g/m²; and the degree of curling—in the knitting width direction—and in the knitting length direction are respectively less than
 20. 5. A method for the production of vehicular upholstery fabric comprising the following steps: knitting a raw tricot fabric by using a polypropyleneterephthalate-multifilament yarn whose single fiber fineness is 0.5˜6.0 dtex and whose total fineness is 30˜180 dtex for the ground yarn and the pile yarn; napping the sinker loop of the pile yarn of the raw tricot fabric to form fluffs; transforming the raw tricot fabric into a napped tricot pile fabric by shearing the napped fluffs to form cut piles; neatly spreading the napped tricot pile fabric; heating the spreaded napped tricot pile fabric by straining in the knitting width direction but without straining in the knitting length direction, thus relieving a potential stress—of the needle loop of the ground yarn stored during the knitting process; heating—the napped tricot pile fabric by the same straining process such that—the density of the wale of the cut pile is more than 30 W/25.4 mm, the density of the course of the cut pile is more than 50 C/25.4 mm, and the density of the knit loop, which is defined by the product of the density of the wale of the cut pile and the density of the course of the cut pile, is from 1800 to 2300 C×W/(25.4 mm)².
 6. A vehicular upholstery polypropyleneterephthalate fiber fabric according to claim 2, wherein: the single fiber fineness of the polypropylenetherephthalate-multifilament yarn is 0.5˜6.0 dtex; the total finess of polypropyleneterephthalate-multifilament yarn is 30˜180 dtex; the density of the wale of the vehicular upholstery polypropyleneterephthalate-fiber fabric is more than 30 W/25.4 mm; the density of the course of the vehicular upholstery polypropyleneterephthalate-fiber fabric is more than 50 C/25.4 mm; the density of the knit looop, which is defined by the product of the density of the wale and the density of the course, is 1800 to 2300 C×W/(25.4 mm)²; the basis weight of the vehicular upholstery polypropyleneterephthalate-fiber fabric has been set at more than 450 g/m²; and the degree of curling in the knitting width direction and in the knitting length direction are respectively less than
 20. 7. A vehicular upholstery polypropyleneterephthalate fiber fabric according to claim 3, wherein: the single fiber fineness of the polypropylenetherephthalate-multifilament yarn is 0.5˜6.0 dtex; the total finess of polypropyleneterephthalate-multifilament yarn is 30˜180 dtex; the density of the wale of the vehicular upholstery polypropyleneterephthalate-fiber fabric is more than 30 W/25.4 mm; the density of the course of the vehicular upholstery polypropyleneterephthalate-fiber fabric is more than 50 C/25.4 mm; the density of the knit looop, which is defined by the product of the density of the wale and the density of the course, is 1800 to 2300 C×W/(25.4 mm)²; the basis weight of the vehicular upholstery polypropyleneterephthalate-fiber fabric has been set at more than 450 g/m²; and the degree of curling in the knitting width direction and in the knitting length direction are respectively less than
 20. 